PVID: An interactive Matlab application for parameter identification of complete and simplified single-diode PV models

This paper introduces PVID, an interactive application for performing parameter identification of both complete (5-parameter) and simplified (4-parameter) single-diode photovoltaic (PV) models. Two equations are presented that allow to perform on-line 4-parameter identification without exploiting iterative methods. They are useful, for example, to support a maximum power point tracking (MPPT) algorithm. On the other hand, the 5-parameter identification is based on an inherently iterative algorithm. User can interactively simulate the behavior of both models and compare their ability to reconstruct the current-voltage curve of the PV source. Moreover, since iterative methods could return a wrong solution, PVID also allows to select arbitrary initial conditions to verify their effect on the reconstruction of the current-voltage curve. Finally, the user can evaluate whether/how much the maximum power point moves when the initial conditions are varied. A verification of the effectiveness of the proposed tool against measured data of commercial PV modules is given. The proposed application can be advantageously applied for educational purpose to better understand the potential and the limitations of the different PV models and their parameter identification procedures.